#separation

How detailed should the divorce conversation be with children?

The kids were asking me the other day about dad not living in the house and us being separated. I told them the same thing I always say, that we are better people and parents this way. Then they asked who left first. I paused and just said what we had told them originally.
Later, it got me thinking if that was the best approach. I think they blame me for the whole thing so part of me wants to tell them exactly what happened. Is that wise?